Counter recoil mechanism



NOV. 5, 1968 CHOLIN 3,409,232

COUNTER RECOIL MECHANISM Filed Jan 6, 1966 aim-5:!

United States Patent 3,409,232 COUNTER RECOIL MECHANISM Roger R. Choliu, Westchester, N.Y. (175 Saw Mill River Road, Elmsford, N.Y. 10461) Filed Jan. 6, 1966, Ser. No. 519,079 1 Claim. (Cl. 239-499) This invention relates to a counter-recoil mechanism used on fire extinguishers of large capacity.

To hold onto a discharging nozzle of a dry powder fire extinguisher of the wheeled tank type is very diflicult for one man because of the reaction pressure on the hose from which the high pressure nitrogen gas and its dry powder chemicals issue.

The device of this invention lessens this reaction pressure on the hose nozzle held by the operator.

It is an object of this invention to provide a mechanism to minimize the reaction pressure on a nozzle disposed on a flexible hose of a high pressure gas line.

This and other objects of this invention will become apparent upon reading the following descriptive disclosure taken in conjunction with the illustrative embodiment shown in the accompanying drawing in which:

FIG. 1 is a cross section of a cylindrical counter-recoil device having a plurality of top and bottom slot apertures and having a cylindrical non-perforated shield secured thereto,

FIG. 2 is a section view taken substantially on line 22 of FIG. 1,

FIG. 3 is an end view of the device and shield therearound, and

FIG. 4 is a section view taken on line 4-4 of FIG. 1.

Turning to the drawing, the device is provided with a cylindrical metal body having a pair of rows of slots or elongated apertures 11 disposed diametrically opposed to one another.

The apertures 11 are of a relatively large area to permit rapid reduction of gas pressure as the gas travels away from the metal nozzle 12 secured to the hose.

The body 10 is provided with an integral conical portion 13 which in turn is integral to an externally threaded nipple portion 14 which is threaded into the internally threaded nozzle 12.

The slots 11 are cut along the length of the cylinder 10 and extend from a point close to the conical portion 13 to a point adjacent the front opening or orifice 15.

Preferably the slots 11 are provided with the rear walls 16 sloped rearwardly at a slight angle to effect a better diminution of the recoil pressure.

The apertures shown in the drawing are shown as slots disposed in two rows but other configurations of apertures, for example, round apertures are operable but less effective.

Where other types of apertures are used, they need not be disposed in diametrically opposed rows but they may be circumferentially disposed around the body 10.

When the body 10 is used on a high pressure dry powder fire extinguishing nozzle 12, the finely divided dry powder issuing from the apertures 11 forms a dense dusty cloud that covers the operator of the nozzle to his discomfort.

To lessen this discomfort, the body 10 is provided with at least a pair of suitably spaced apart threaded apertures 18.

A non-perforated shield 19 of relatively larger diameter than the body 10 is provided with an apert-ured end wall 20 to receive the nipple portion 14 and it also is provided with at least one pair of bolt receiving aperture-s 21 adapted to overlie apertures 18 of the body 10.

In order to suitably space the shield 19 away from the body 10 a round collar or spacer 22 is disposed about the apertures 18 and a bolt 23 is screwed into each of the apertures 18 through the respective apertures 21 and collars 22.

As shown in FIG. -2, a double row of bolts 23 and their co-acting spacers 22 may be used, if desired, for a more rigid securing of the shield 19 to the body 10.

In the operation of the counter-recoil mechanism of this invention, the gas issuing from the nozzle 12 also issues from the orifice 15 of the body 10.

However, a small amount of gas after expanding in conical portion 13 is forced out of the unique apertures 11 thereby gradually relieving the gas pressure of its recoil elfect in an even manner. The apertures 11 by having one wall 16 sloped to the rear smoothly and more effectively reduce the back pressure on the operator of the nozzle 12 than is the case where both of the aperture walls are parallel to one another and perpendicular to the axis of the body 10.

This invention was described by means of an illustrative embodiment but it is not limited thereto.

I claim:

1. A tubular counter recoil mechanism for securing to a threaded nozzle of a high gas pressure discharge hose comprising a tubular cylindrical body having a linear pair of opposed rows of slot apertures down the length thereof, said apertures being in substantially tranverse relationship to the direction of the gas stream and having a front wall perpendicular to the gas stream and a rear wall sloped away from the movement of said gas stream, said body having a front discharge orifice and a rear conical tubular portion, said conical portion being into gral to a threaded tubular nipple portion for attachment to said nozzle and a cylindrical shield of suitably larger diameter than said body, said shield having a rear wall having an opening therein to receive said nipple portion, and securing means for securing said shield to said body in a uniform rigid spaced-apart relationship, whereby a gas stream issuing through said nipple expands in said conical portion and is forced through said body with uniform loss of recoil pressure until said stream reaches said orifice.

References Cited UNITED STATES PATENTS 3/1935 Allen et al. 169-11 3/1951 Frese et al. l69-ll EVERETT W. KIRBY, Primary Examiner. 

1. A TUBULAR COUNTER RECOIL MECHANISM FOR SECURING TO A THREADED NOZZLE OF A HIGH GAS PRESSURE DISCHARGE HOSE COMPRISING A TUBULAR CYLINDRICAL BODY HAVING A LINEAR PAIR OF OPPOSED ROWS OF SLOT APERTURES DOWN THE LENGTH THEREOF, SAID APERTURES BEING IN SUBSTANTIALLY TRANVERSE RELATIONSHIP TO THE DIRECTION OF THE GAS STREAM AND HAVING A FRONT WALL PERPENDICULAR TO THE GAS STREAM AND A REAR WALL SLOPED AWAY FROM THE MOVEMENT OF SAID GAS STREAM, SAID BODY HAVING A FRONT DISCHARGE ORIFICE AND A REAR CONICAL TUBULAR PORTION, SAID CONICAL PORTION BEING INTEGRAL TO A THREADED TUBULAR NIPPLE PORTION FOR ATTACHMENT TO SAID NOZZLE AND A CYLINDRICAL SHIELD OF SUITABLY LARGER DIAMETER THAN SAID BODY, SAID SHIELD HAVING A REAR WALL HAVING AN OPENING THEREIN TO RECEIVE SAID NIPPLE PORTION, AND SECURING MEANS FOR SECURING SAID SHIELD TO SAID BODY IN A UNIFORM RIGID SPACED-APART RELATIONSHIP, WHEREBY A GAS STREAM ISSUING THROUGH SAID NIPPLE EXPANDS IN SAID CONICAL PORTION AND IS FORCED THROUGH SAID BODY WITH UNIFORM LOSS OF RECOIL PRESSURE UNTIL SAID STREAM REACHES SAID ORIFICE. 